Table 2

Prognostic value of clinical, radiographic, molecular and MRI-based risk factors: mean values and variability in knees with radiographic osteoarthritis (ROA) which displayed no change in cartilage thickness (no progression) vs those which displayed cartilage thinning over 24 months

ROA no change (n=45)ROA thinning (n=19)
Risk factorMeanSDMeanSDPercentage differenceAUC (ROC)p Value (Wilcoxon)
Age (years)
BMI (kg/m2)33.76.637.16.410.20.6210.1310
mJSW (mm)4.030.883.170.99−21.40.7380.0035
Anat. alignm. axis (°)181.32.4178.82.5−1.40.7670.0012
ln sIntactPINP3.690.373.550.63−3.80.6170.1877
ln sCTXI−1.360.64−1.670.78−22.70.6540.0441
ln pNPII0.460.900.881.0192.90.6420.1013
ln uTINE_Cr3.180.693.250.702.20.5520.5010
ln sCPII5.870.365.850.30−0.40.5260.7133
ln sPIIANP6.600.756.530.66−1.10.5230.9349
ln uCTXII_Cr5.350.595.410.461.10.5460.6088
ln uARGS_Cr−0.780.71−0.771.081.30.5150.8672
ln sCOMP2.360.282.330.29−1.00.5160.9531
ln uTIINE_Cr4.460.614.480.670.40.5280.7231
ln p15HETE5.630.625.620.63−0.20.4890.8890
ln pPGE23.750.953.840.772.30.4921.0000
ln uOsteop_Cr1.311.101.221.24−7.50.4840.8882
ln sPIIINP1.320.341.210.33−8.00.5570.3977
ln uTIIINE_Cr5.450.715.440.76−0.30.4750.7309
ln p3-NT7.250.407.250.510.00.4700.7842
Menisc_height (mm)−8.30.5150.8017
Menisc_sublux (mm)0.420.170.480.1414.70.6300.0962
ThCtAB_MT (mm)1.670.191.620.21−3.10.5680.4223
ThCtAB_cMF (mm)1.800.241.460.32−18.80.8050.0001
  • The table reports bivariate analyses (progression vs no progression) without adjustment for other factors.

  • p Value, level of significance of differences between ROA knees with cartilage thinning vs those without significant change, determined using the Wilcoxon Rank Sum test (Fisher Exact test was used for ordinal variables, ie, OP and JSN scores). A p value given bold and in italics was significant at p<0.05 after correction for multiple testing using false discover rates (FDR); a p value given in italics was significant at p<0.05 before, but not after correction for multiple testing

  • anat. alignment axis, anatomical knee axis determined from the Lyon Schuss (LS) radiographs (note there is an approximate 4° offset with the mechanical knee axis, ie, 184° is considered neutral alignment); BMI, body mass index; cMF, medial weightbearing femur; dGEMRIC, delayed gadolinium-enhanced MRI; MFTC, medial femorotibial compartment; menisc. height, meniscal height; menisc. Sublux, meniscal subluxation; Menisc_%Cover, percentage of tibial plateau covered by meniscus; mJSW, minimal joint space width measured quantitatively in LS radiographs; molecular markers (ln, natural logarithmic transformation) from urine (u), plasma (p), or serum (s): sIntactPINP, (intact) N-terminal propeptide of type I procollagen (μg/l); MT, medial tibia; OP, ordinal osteophyte scores (range 0–3) and JSN, ordinal joint space narrowing scores (range 0–3) obtained using LS radiographs and the Osteoarthritis Research Society International atlas in the MT and in the cMF; pNPII, N-terminal propeptide of type II procollagen (ng/ml), sCPII, C-terminal propeptide of type II procollagen (ng/ml); pPGE2, prostaglandin E2 (pg/ml); ROC, receiver operator characteristic; sCOMP, cartilage oligomeric matrix protein (U/l); sCTXI, C-terminal telopeptide of type I collagen (ng/ml); sPIIANP, N-terminal propeptide of type IIA procollagen (ng/ml); sPIIINP, N-terminal propeptide type III procollagen (ng/ml); ThCtAB, mean thickness (averaged over the total area of subchondral bone (tAB) in the MT and in the cMF); uARGS, aggrecan ARGS neoepitope (ng/mg creatinine): p15HETE, hydroxyeicosatetraenoic acid (pg/ml); uCTXII, C-terminal telopeptide of type II collagen (ng/mmol creatinine); uOsteop, osteopontin neoepitope peptide (ng/mg creatinine): p3-NT, plasma 3-nitrotyrosine (pg/ml); uTIIINE, type III collagen neoepitope (ng/mg creatinine); uTIINE, type II collagen neoepitope (ng/mmol creatinine); uTINE, type I collagen neoepitope peptides (ng/mg creatinine); WOMAC, Western Ontario and McMaster Universities scores: ranges are 0–20 for pain, 0–8 for stiffness and 0–68 for function (with higher values indicating more pain, more stiffness and worse function).